JPH02274482A - Bilateral master slave manipulator - Google Patents

Abstract

PURPOSE:To faithfully transmit the loading state of a slave arm to a master side by providing a powder brake as the actuator of the joint of a master arm which is equipped with an operation gripper and operated thereby. CONSTITUTION:A powder brake 18 is used for generating restraint in a master arm joint. A large binding torque of high accuracy excellent in responsibility and receiving no effect of a master arm 11 operation speed can thus be obtained. Also, due to no speed reducer being used in the master arm 11, the loss torque of a friction torque, etc., can be minimized and a force feedback in a no load state can be achieved.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention provides a master-slave manipulator, particularly a slave arm, that can remotely perform work in an environment inaccessible to a single person such as a nuclear fuel reprocessing plant. It relates to a pirate master manipulator that feeds back the working force acting on it to the operator.

(Prior Art) FIGS. 5A to 5B show schematic configurations of three types of conventional typical pirated master-slave manipulators.
The one shown in Figure A is a symmetrical type, the one shown in Figure 5 is a force reversal type, and the one shown in Figure 5C is a force return type. In these figures, both the mask side arm 1 and the slave side arm 2 are driven by electric motors. Therefore, Figure 5A
In the symmetrical type, the position detector 3 provided on each arm
The detection outputs θ□ and θ2 of 0.4 are compared in a comparator circuit 5, and the output of the comparator circuit 5 controls the electric motors that drive the respective arms via position adjusters 6 and 7.

In addition, in the force reverse feed type shown in FIG. ing.

In the force feedback type shown in FIG.
The output of this comparison circuit is fed back to the control mechanism of the mask-side arm 1 via the torque regulator 12.

In any of the above master-slave manipulators, the work load acting on the slave arm 2 is transmitted to the control mechanism of the mask arm 1, and the operator knows the work load acting on the slave arm 2 when operating the manipulator. be able to.

(Problems to be Solved by the Invention) In any of the conventional pirated master-slave manipulators listed above, the operability of the master arm is influenced by the servo system adopted on the mask side. Normally, a reducer with a high reduction ratio is interposed between the drive motor and the driven arm, so it is not possible to operate the master arm 1 at the speed the operator expects, and there is a slave on the mask side. There is a drawback that the load state of the arm 2 is not faithfully transmitted.

In order to eliminate these drawbacks, a direct drive master arm that does not involve a reduction gear has been proposed, but this method has drawbacks such as the size and weight of the master arm becoming larger and the system becoming more expensive. Therefore, there were problems in putting it into practical use.

The present invention has been made based on the above circumstances, and can faithfully transmit the load state of the slave arm to the mask side, and can be constructed at a relatively low cost without increasing the size or weight of the master arm. It aims to provide a pirated master-slave manipulator.

[Structure of the Invention] (Means for Solving the Problems) The pilateral master-slave manipulator of the present invention is provided with a powder brake as an actuator of the joint at the joint of a master arm which is provided with an operation gripper and which is operated by the operation gripper, and which is operated by the operation gripper. A drive unit for driving the joint by a deceleration motor with a brake is provided at the corresponding joint of the slave arm, which is equipped with a robot hand that follows the movement of the master arm driven by the master arm and is operated by the operation gripper. The drive unit is provided with a potentiometer that detects the angle of each joint, and a control computer is provided that controls the powder brake and the drive unit based on the output of each potentiometer.

(Function) In the pilateral master-slave manipulator of the present invention having the above configuration, since the powder brake is used to generate a restraining force at the master arm joint, it has excellent responsiveness and is not affected by the master arm operating speed. A highly accurate locking torque can be obtained. Further, since no reduction gear is used in the master arm, loss torque such as friction torque can be minimized, and force feedback in a no-load state can be achieved.

(Embodiment) FIG. 1 is a perspective view of one embodiment of the present invention. In this figure, master arm 11. The slave arm 12 has the same structure and is a multi-joint robot arm with multiple degrees of freedom, including axes of movement such as one rotation, swing, expansion and contraction, etc. In this example, 6
It is assumed that there is a degree of freedom. A mine operation gripper 13 is provided at the tip of the master arm 11, and the slave arm 1
A robot hand 14 is provided at the tip of the robot hand 2'. A six-axis sensor 15 is provided between the tip of each arm and the operating gripper 13 and the robot hand 14, respectively.
16 are provided. A powder brake 18 is provided at the joint between links 17a and 17b constituting the master arm 11. In addition, 19 is the master arm base, 2
0 indicates counterweight, while slave arm 1
A drive section 22 is provided at the joint between the two links 21a and 21b. Note that 23 indicates a slave arm base.

FIG. 2 is a diagram showing a swing joint of the master arm 11 using the powder brake 18 as an actuator. In this figure, a link 17b that swings relative to the link 17a is a shaft 2 that is rotatably supported by a bearing 24 at the tip of the link 17a.
5, and the powder brake 18 applies a braking force to the shaft 25. Further, a shaft 26a of a potentiometer 26 is fixed to the shaft 25, and the potentiometer 26 is designed to detect the rotation angle of the shaft 25.

FIG. 3 is a diagram showing a swing joint in the slave arm 12. In this figure, a shaft 27 is fixed to a link 21b that swings relative to the link 21a, and this shaft is rotatably supported by a bearing 28 at the tip of the link 21a. Note that the drive unit 22 has a reduction motor 22a with a brake,
The output shaft 29 is fixed to the shaft 27 in Figure 0,
22b is a brake, 22c is a speed reducer, and 22d is an encoder. Further, a shaft 30a of a potentiometer 30 is fixed to the shaft 27.
The rotation angle of the shaft 27 is detected by this.

FIG. 4 shows the electrical control circuit of this embodiment. This control circuit amplifies the output of the control computer 31.6-axis force sensor 15.16 and sends the 6-axis force sensor signal 32.33 to the computer 31.
34.35. A powder brake servo amplifier 37 that receives an applied voltage command 36 from a computer 31 and drives the powder brake 18, and a potentiometer 2 whose shaft is connected to the powder brake 18.
A/D converter 39 which inputs the output of 6 to the computer 31 as a digital potentiometer signal 38, and the computer 3.
A motor servo amplifier 41 receives a command current signal 40 emitted by the drive unit 1, and controls the motor 22a of the drive unit 22 by this signal and the encoder output fed back from the encoder 22d. A/
It has a D converter 43.

With the control circuit having the above configuration, the master arm 11 drives and controls the slave arm 12 in the following manner. That is, 1. Normally, the computer 31 controls the drive section 22 that drives the slave arm 12 using the output of the potentiometer 26 of the joint of the master arm 11, and causes the joint of the slave arm 12 to bend in accordance with the bending of the joint of the master arm 11. Have them do it. Now, here and there, slave arm 12
If the working load torque acting on the links 21a, 21b of the slave arm 12 is larger than the restraining force between the corresponding links 17a, 17b of the master arm 11, the links 21a, 21b of the slave arm 12 may
7b, if the workload torque increases due to this tracking, torque control is performed to control the corresponding torque of the joint of the master arm 11 to follow the torque. This control is performed by the computer 31. That is, the computer 31 performs arithmetic processing using the potentiometer signal 38, which is the output of the potentiometers 26 and 30, and the six-axis force sensor signal 32, which is the digital output of the six-axis force sensor 15. 40 is output to the servo amplifier 41 for controlling the electric motor 22a to execute the torque follow-up control.

The torque T of each joint can be obtained from the following equation using the force acting on the arm tip→F・moment M and the transposed matrix of the Jacobian matrix J.

In 22, the force F and moment M related to the tip of the arm are directly determined from the outputs of the six-axis force sensors 15 and 16. Also,
The transposed matrix J1 of the Jacobian matrix J can be obtained by calculating the operating angle of each joint from the output of the potentiometer 26, 30 of each joint.

Next, control of the master arm 11 will be explained. A powder brake 18 provided at the joint between the links 17a and 17b of the master arm 11 is controlled by the work load applied to the tip of the slave arm 12. That is, the restraint torque TMI at link i obtained from equation (1), and the work load torque T! of the slave arm 12! The target brake torque TRI to be applied to the link i from 1 is given by the following formula (2)
required from.

TMlXT, 1) When O, TM, is applied to the powder brake servo amplifier 37, and the powder brake 18 is controlled to apply the brake force Ts+.

As is clear from the above, the pirated master-slave manipulator of the present invention has a very simple configuration and can be provided at low cost.

The pilateral master-slave manipulator of the present invention uses a powder brake to generate a restraining force at the master arm joint, thereby obtaining a large restraining torque with excellent responsiveness and high precision that is unaffected by the master arm operating speed. be able to. Further, since no reduction gear is used in the master arm, loss torque such as friction torque can be minimized, and force feedback in a no-load state can be achieved.

Further, in the pirated master-slave manipulator of the present invention, force is returned to the master arm 11 only when the slave arm 12 is operated in a direction where the load increases, thereby exerting a bidirectional effect. The slave arm 12 can be moved at high speed in free space without the need for. In other words, in the conventional bidirectional manipulator, when performing the above-mentioned high-speed movement, the operational load on the master arm 11 cannot be completely reduced to zero due to the limitations of the drive control system.
This causes operator fatigue and prevents the reproduction of a sense of remote presence.However, in the pirated master-slave manipulator of the present invention, when the work load of the slave arm 12 is O as described above, Master arm 1
Since the powder brake 18 of No. 1 will be released,
The master arm 11 can be operated completely without any load.

By operating this at high speed, the slave arm 12 can be moved at high speed.

Furthermore, if the load torque on each joint of the slave arm 12 is greater than the restraint force on each joint of the master arm 11, and the slave arm 12 follows the master arm 11 in position, the load on the slave arm 12 will further increase. In such cases, torque follow-up control is performed in which the torque of each joint of the slave arm 12 follows the torque of each joint of the master arm 11. Therefore, when an unintended large work load is applied to the slave arm 12, The slave arm 12 is immediately controlled and the second work load is transferred to the master arm 11.
be lowered to the level indicated by.

[Effects of the Invention] As is clear from the above, although the pilateral master-slave manipulator of the present invention has a simple structure and can be provided at low cost, the work load on the slave arm side is faithfully transferred to the master arm side. If an excessive workload is applied, it can be automatically reduced to the appropriate level required by the master arm.

[Brief explanation of drawings]

FIG. 1 is a perspective view of one embodiment of the present invention, a second example is a sectional view of the main part of the master arm of the embodiment, FIG. 3 is a sectional view of the main part of the slave arm, and FIG. 4 is a sectional view of the main part of the slave arm of the embodiment. Flowcharts of the electrical control circuit, FIGS. 5A to 5C, are schematic configuration diagrams showing three typical examples of conventional pirated master-slave manipulators. 11... Master arm 12... Slave arm 13... Operation gripper 14...
...Robot Hakado 15.16...6-axis sensor 17a, 17b, 21a, 21b...
・Link 18...Powder brake 19.2
3...Base 20...Counterweight 24.28...Bearing 25.27°29.
26a, 30a-axis 26.30--Potentiometer 31...Control computer 32,33-
...6-axis force sensor signal 34.35...
Amplifier for 6-axis force sensor 36... Applied voltage command signal 37... Servo amplifier for powder brake 38, 42... Potentiometer signal 39
．． 43...A/D converter 40...
・Command current signal 41... Servo amplifier for motor

Claims (1)

[Claims] A slave arm that is equipped with an operation gripper and that is provided with a powder brake as a joint actuator at the joint of a master arm that is operated by the operation gripper, and that is equipped with a robot hand that follows the movement of the master arm that is driven by the operation gripper and is operated by the operation gripper. A driving section for driving the joint by a deceleration motor with a brake is provided at the corresponding joint, and a potentiometer for detecting the angle of each joint is provided for the powder brake and the driving section, and the powder brake is controlled by the output of each potentiometer. and a control computer that controls the drive section.